NEW ORLEANS — The U.S. Coast Guard Captain of the Port for Morgan City, La., issued a Notice of Federal Interest to Transocean Holdings, LLC, Tuesday.

A series of sheen sightings in the area of Mississippi Canyon block 252 indicate the possibility of a release from the riser pipe or other debris on the ocean floor from the April 20, 2010, Deepwater Horizon incident. Recent ROV video footage of the capped Macondo well has shown no evidence of a release from the well.

An NOFI puts a potential responsible party on notice and, under the Oil Pollution Act of 1990, the responsible party may be financially accountable for debris removal costs and damages resulting from the pollution incident. Federal removal actions will be limited to monitoring progress of the responsible party's actions and providing guidance as necessary.

"This is part of the process we take whenever there is an oil sighting that cannot be immediately attributed to a specific source. We will actively work with Transocean to discuss options to determine whether or not the wreckage is the cause," said Capt. Jonathan Burton, commanding officer of Marine Safety Unit Morgan City.

Failure or refusal of the responsible party to provide all reasonable cooperation and assistance requested by the Federal On-Scene Coordinator will eliminate any defense or entitlement to limited liability, which might otherwise be available under OPA 90, and subject them to significant fines under the Federal Water Pollution Act.